canuckxxxx's Single carb manifold build

[slabghost]

Come on spring!

 

[dan filipi]

Brian, could you refresh memory on how it ran before, what you've done since, and what differences you notice now?

 

[canuckxxxx]

If you go back to very beginning of this thread you can see that I put the whole thing together and had it running pretty quickly. Idled nice but when I took it for a test run I had a big time hesitation when I tried to accelerate off of idle...like when the light turns green and I gave it some gas and let the clutch out it would just suddenly die. Or when I went around a corner and went to accelerate out of it it would just die. Once the revs got up it would go hard so I knew there was potential. I tried swapping the primary (50) and secondary (60) low speed jets and the richer mixture really helped the hesitation. But the weather never allowed me to road test this setup.

From reading what Tom Langdon, Dan and other said I knew that heat was needed at the plenum. I really didn't want to take the whole cooling system apart so I thought I could cast an aluminum mass that would conduct heat from the coolant plumbing on the top of the engine to the bottom of the plenum. But I looked at the cost of getting it cast and questionable potential so I took the plunge and took the top plumbing off and the rad hose spigot at the pump suction. It really was not hard to do.

I bought a piece of 1/8" thick al sheet and formed a piece to close in the bottom of the plenum and had fittings for IN/OUT for the coolant. Drilled and tapped a 1/4" NPT hole at the end of the coolant centre section for a coolant supply. Made a 1/2" thick insert to go between the bottom rad hose spigot and the pump cover with 3/8" hole through the side for a return. I really think this is the simplest and least invasive way of heating the plenum.

It all went together pretty well then. With hot coolant flowing through the plenum it got nice and warm. I swapped the jets back to their original position and the big hesitation that I experienced before seems to be completely eliminated. I found a way of testing for hesitation in my driveway by doing aggressive launches; that is, with engine idling, giving it gas and letting the clutch out quickly. Then try and stop before hitting the end of the garage. I'm sure the neighbours found this entertaining.

I am really looking forward to getting the old beast out on the road and see how it performs.

I must give credit to this forum for my success. Almost everything I did was because Dan or Joe or someone else had tried it and proved that it worked. More of a team success really. I was glad that I could contribute the insert plate at the pump suction for a return.

Brian

 

[ekvh]

Then try and stop before hitting the end of the garage. I'm sure the neighbours found this entertaining.
You could be my neighbor, errrr neighbour. I would find that entertaining. I have enjoyed following your build.

 

[joedrum]

I agree a great job ... it is like all over our forum we have people doing different things shedding light on the way to do and how successful and here for others to learn ... the collection of info and contributors make this a great info and outcome forum just as dan wanted for this forum and we all have made huge contribution to the forum success and the oldwings that get fixed and running ...

as single carbs go brian this is quite the info read and still going ... no place has the info and collaboration been so good on single carb mods ...

 

[dan filipi]

canuckxxxx » Tue Feb 11, 2014 6:33 pm[/url]":cnknkgzw]
If you go back to very beginning of this thread you can see that I put the whole thing together and had it running pretty quickly. Idled nice but when I took it for a test run I had a big time hesitation when I tried to accelerate off of idle...like when the light turns green and I gave it some gas and let the clutch out it would just suddenly die. Or when I went around a corner and went to accelerate out of it it would just die. Once the revs got up it would go hard so I knew there was potential. I tried swapping the primary (50) and secondary (60) low speed jets and the richer mixture really helped the hesitation. But the weather never allowed me to road test this setup.

From reading what Tom Langdon, Dan and other said I knew that heat was needed at the plenum. I really didn't want to take the whole cooling system apart so I thought I could cast an aluminum mass that would conduct heat from the coolant plumbing on the top of the engine to the bottom of the plenum. But I looked at the cost of getting it cast and questionable potential so I took the plunge and took the top plumbing off and the rad hose spigot at the pump suction. It really was not hard to do.

I bought a piece of 1/8" thick al sheet and formed a piece to close in the bottom of the plenum and had fittings for IN/OUT for the coolant. Drilled and tapped a 1/4" NPT hole at the end of the coolant centre section for a coolant supply. Made a 1/2" thick insert to go between the bottom rad hose spigot and the pump cover with 3/8" hole through the side for a return. I really think this is the simplest and least invasive way of heating the plenum.

It all went together pretty well then. With hot coolant flowing through the plenum it got nice and warm. I swapped the jets back to their original position and the big hesitation that I experienced before seems to be completely eliminated. I found a way of testing for hesitation in my driveway by doing aggressive launches; that is, with engine idling, giving it gas and letting the clutch out quickly. Then try and stop before hitting the end of the garage. I'm sure the neighbours found this entertaining.

I am really looking forward to getting the old beast out on the road and see how it performs.

I must give credit to this forum for my success. Almost everything I did was because Dan or Joe or someone else had tried it and proved that it worked. More of a team success really. I was glad that I could contribute the insert plate at the pump suction for a return.

Brian

In the before and after, did you add the 2 to 1 adaptor?

 

[canuckxxxx]

No, Dan, I never tried the 2 inti 1.

 

[canuckxxxx]

But that is just because I have done 0 road testing with my setup. That is a refinement that may come later.

Brian

 

[joedrum]

cant say it enough how great your work has been

 

[canuckxxxx]

Well we got a little break in the weather here in Alberta. It's been around 0C to 4C the last few days. Today the roads looked dry enough for a ride so I got to do an unexpected test ride. Pretty good ride actually; about 45 minutes and included some highway kilometers.

I can say that the bike ran flawlessly. Absolutely no hesitation or bogging at all. Seems to have more low RPM torque so likes to be short shifted which is what I like to do anyway (I'm an old guy). It will pull cleanly and strongly from 3000 RPM in top gear.

With my gearing it is turning about 3700 RPM at 60MPH. With the OEM carbs it never felt like it was happy at that low a speed in top gear unless I was going on the level or down hill. In the mountains I would use 4th gear for the rolling roads. With the single carb it is a lot more confident in top gear at 60MPH.

I don't think the top end rush is a good as with the OEM rack. I mean the 2nd or 3rd gear rush from 5000 to 8000 RPM. Not sure, only tried that a few times. But I don't usually ride that way anyway.

Very happy with it. Ran good, no leaks. Ready for spring. When it cools off I will pull the plugs and see how it is running.

I must say that it was running rather cool the whole time. The outside air temp was only 3C (37F) so maybe that is why. The temp gauge never even got to the end of the narrow part of the gauge line; where the T stat usually seems to open.

Brian

 

[canuckxxxx]

I've changed the flow pattern of the cooling system with the addition of the plenum heater. The plenum absorbs some heat plus there is a lot more coolant circulation before the T stat opens compared to the stock setup. The stock bypass is tiny compared to the 1/2" hose that now goes directly to the pump suction as well as the stock bypass.

I suppose there could be some harm done by the engine taking a very long time to reach operating temperature. What do you guys think? Is the temperature gauge still giving an accurate measure of the coolant temperature since most of the flow does not go past the temperature sensor now?

Brian

 

[dan filipi]

canuckxxxx » Fri Feb 14, 2014 3:10 pm[/url]":kfjt2hkj]
I've changed the flow pattern of the cooling system with the addition of the plenum heater. The plenum absorbs some heat plus there is a lot more coolant circulation before the T stat opens compared to the stock setup. The stock bypass is tiny compared to the 1/2" hose that now goes directly to the pump suction as well as the stock bypass.

I suppose there could be some harm done by the engine taking a very long time to reach operating temperature. What do you guys think? Is the temperature gauge still giving an accurate measure of the coolant temperature since most of the flow does not go past the temperature sensor now?

Brian

I'm still thinking about that one.
Mine takes about the same time to warm up, probably because it isn't so cold.
I'm thinking about putting a valve inline to make some tests, maybe run it then close an see if the temp rises fast. Not sure what indication would be accurate.
What are your thoughts?

 

[joedrum]

well it is a bypass as big as the flow is hmmmmm .. may never open ....sheesh it rgistor temp it don't see ...hmmmm

 

[slabghost]

I doubt there will be any harm. but it does seem to be effectively eliminating the t stat.

 

[canuckxxxx]

dan filipi » Fri Feb 14, 2014 4:15 pm[/url]":1jx23vbb]

canuckxxxx » Fri Feb 14, 2014 3:10 pm[/url]":1jx23vbb]
I've changed the flow pattern of the cooling system with the addition of the plenum heater. The plenum absorbs some heat plus there is a lot more coolant circulation before the T stat opens compared to the stock setup. The stock bypass is tiny compared to the 1/2" hose that now goes directly to the pump suction as well as the stock bypass.

I suppose there could be some harm done by the engine taking a very long time to reach operating temperature. What do you guys think? Is the temperature gauge still giving an accurate measure of the coolant temperature since most of the flow does not go past the temperature sensor now?

Brian

I'm still thinking about that one.
Mine takes about the same time to warm up, probably because it isn't so cold.
I'm thinking about putting a valve inline to make some tests, maybe run it then close an see if the temp rises fast. Not sure what indication would be accurate.
What are your thoughts?

I am thinking that all the coolant within the engine is very close to the same temperature. The temperature sensor is on the engine side of the T stat so it should give a pretty close temperature measure.

But, with that OEM coolant bypass being so small, I am thinking that maybe Honda wanted the coolant to circulate around very slowly and maybe heat up faster. (Not even sure it would heat up faster by circulating slower). Now with my setup the coolant is circulating around more.

To be honest I never paid that much attention to the temperature with the OEM rack so maybe it isn't that much different that before.

Brian

 

[canuckxxxx]

slabghost » Fri Feb 14, 2014 4:19 pm[/url]":1rdiczsr]
I doubt there will be any harm. but it does seem to be effectively eliminating the t stat.

I think you are right. The temps I was riding at were very cold so it's not typical riding conditions. Will have to see how it goes when it's 15 to 20C. If T stat still doesn't open then I can get rid of the radiator which would save some weight.

Brian

 

[slabghost]

As is it still uses the radiator. I doubt you can eliminate it.

 

[canuckxxxx]

Yeah just kidding. Anyways I just pulled the plugs and, as you can see it certainly is not running too rich. Considering the cooling operating conditions, I am wondering if it is running a bit too lean.

156

• canuckxxxx
• Feb 14, 2014

Here is the plug from cylinder #3. You can't see it very well from the picture but those dark patches are glossy.

157

• canuckxxxx
• Feb 14, 2014

What do you guys think. Right now the low speed primary jets is 50 with a 160 air jet, main jet is 95.

Brian

 

[slabghost]

Plugs look healthy to me. Just a little light ash. Definitely not running rich.

 

[joedrum]

hmmmmm looks good in consistent ....hmm you have power valve still in right ?... no telling hoe that and the oldwing motor match up but in general the carbs are set up lean for there application ,,, but if your this far .... and doing this good ...jetting should be optimized to the best .. the weber set up is just to good not to after the best ..when its adjustability is so well built into them